Japan's Revised GDP Growth Exceeds Forecast

Data Boost Case for Sales-Tax Increase

TOKYO—Japan's economy grew at a much faster pace in the second quarter than initially estimated, revised figures show, supplying more ammunition to supporters of a contentious sales tax increase from next spring.

The revised gross domestic product data are one of the key indicators Prime Minister Shinzo Abe has listed as a factor in deciding whether to proceed with the planned tax increase. Monday's strong GDP reading means he has...